1. Field of the Invention
The present invention relates to the general technical field of agricultural machinery and in particular to the field of agricultural machines which comprise a working unit intended, during work, to rest at least partially on the ground and to follow the unevenness of said ground.
The invention relates more particularly to an agricultural machine of this kind which is equipped, on the one hand, with an operating device for raising the working unit into the transport position and for lowering it into the work position and, on the other hand, a lightening device for transferring part of the weight of the working unit onto the chassis.
2. Discussion of the Background
Agricultural machines of this kind, comprising:
a chassis,
a working unit connected to the chassis by means of a suspension device so that it can move relative to the chassis during work,
at least one operating ram for raising said working unit into the transport position or lowering it into the work position relative to the chassis,
and at least one lightening ram for transferring part of the weight of the working unit onto the chassis, are already known.
The operating and lightening ram(s) is (are) connected to one (or more) source(s) of fluid, for example using rigid or flexible pipes. It is therefore important that said rams be secured appropriately to prevent them from rotating on themselves and causing the supply pipes to burst or pull out.
The present invention therefore aims to produce an agricultural machine comprising at least one operating and lightening ram that can move relative to the chassis and relative to the working unit but without being able to rotate on itself.
The objective that the present invention has set itself is achieved using an agricultural machine wherein the (each) operating ram and the (each) lightening ram each comprise a corresponding chamber formed in one same mobile cylinder, each of said chambers being connected to a source of fluid and said cylinder being associated with a corresponding locking means for preventing said cylinder from rotating about its longitudinal axis.